Encapsulation and controlled release of a substance or material may be achieved by a number of methods. Typically, a polymeric coating may be used to either surround a substance or to form a mixture with a substance. Another common approach uses macroscopic structures having openings or membranes that allow for release of a substance. Encapsulation and controlled release finds broad utility, but is particularly useful in the field of controlled release drug delivery.
PCT Publication WO 2005/012488 describes encapsulating a guest molecule (for example, a drug) in a chromonic matrix so that it can be subsequently released. The chromonic matrix can protect a drug from certain environmental conditions and then controllably deliver the drug under other environmental conditions.